The program is designed to provide laboratory training to both M.D. and Ph.D. graduates who have either committed themselves to a career in biomedical research or who are seriously contemplating such a commitment. Broad areas of experimental hematology are covered. These include the biochemistry, physiology and molecular biology of red blood cells, granulocytes, lymphocytes, platelets and clotting factors. Trainees may include physicians who have completed or are in the process of obtaining their training in clinical hematology/oncology and Ph.D. scientists who either have just obtained their degree or who wish to obtain broader training after the completion of two or three years of postdoctoral fellowship elsewhere. M.D. fellows will be derived both from our clinical training program and from training programs in other institutions. Preference will be given to trainees who have had previous laboratory experience;however M.D. candidates who have not had previously extensive laboratory experience but who show a high degree of motivation may be accepted into the program. The facilities for training are in the Department of Molecular and Experimental Medicine of The Scripps Research Institute. The training faculty for this program work in approximately 30,000 square feet of laboratory space used exclusively for biomedical research